- Try to avoid messing up bytecode of the installed pkg

- Add missing dependency on pygal and pygaljs

- Add missing dependency on aspectlib

- Update to 3.2.2:
* Added support for pytest items without funcargs. Fixes interoperability with other pytest plugins like pytest-flake8.
* Added missing version constraint change. Now pytest >= 3.8 is required (due to pytest 4.1 support).
* Fixed couple CI/test issues.
* Fixed broken pytest_benchmark.__version__.
* Added support for simple trial x-axis histogram label. Contributed by Ken Crowell in #95).
* Added support for Pytest 3.3+, Contributed by Julien Nicoulaud in #103.
* Added support for Pytest 4.0. Contributed by Pablo Aguiar in #129 and #130.
* Added support for Pytest 4.1.
* Various formatting, spelling and documentation fixes. Contributed by Ken Crowell, Ofek Lev, Matthew Feickert, Jose Eduardo, Anton Lodder, Alexander Duryagin and Grygorii Iermolenko in #97, #97, #105, #110, #111, #115, #123, #131 and #140.
* Fixed broken pytest_benchmark_update_machine_info hook. Contributed by Alex Ford in #109.
* Fixed bogus xdist warning when using --benchmark-disable. Contributed by Francesco Ballarin in #113.
* Added support for pathlib2. Contributed by Lincoln de Sousa in #114.
* Changed handling so you can use --benchmark-skip and --benchmark-only, with the later having priority. Contributed by Ofek Lev in #116.
* Fixed various CI/testing issues. Contributed by Stanislav Levin in #134, #136 and #138.